This invention relates to a multi-dimensional color image mapping apparatus and method.
Prior art image processing operations may generally be categorized as point to point, matrix or convolution, frequency based, temporal, and geometric. Point to point operations are performed on each pixel in the image. Matrix operations are performed on each pixel, but take into account some finite number of surrounding pixels. Frequency based operations deal with transforming the image mathematically into what is called the frequency domain, and then applying operations on the frequency domain before converting the image back to its original format. Temporal processing operations deal with multiple frames in a sequence over time (moving pictures). Geometric operations perform image rotation, scaling, translation and resizing (resampling), among others. The current span of technology for enhancing images performs changes on an image that are broad in scope and therefore, while improving an image in certain areas, they create problems in others. Electronically captured images, particularly video (NTSC, PAL, or hi-definition video) are inherently uneven. They are uneven in terms of light level, color level, color and edge representation, among others. Because they are uneven, applying prior art imaging processing operations to the image results in a processed image that still contains its inherent "unevenness". That is, certain portions of the image improve while others are taken "over the edge".
U.S. Pat. No. 4,935,816 to Faber is illustrative of the current state of the art in some image enhancement and modification techniques. For a variety of reasons, discussed further hereafter, video taped images are less appealing to the human eye than film images. One of the differences, generally subtle and overlooked by the viewer, is that film has "grain". Faber looks to enhance video taped images by, among other things, the addition of mixed, clipped and filtered noise so as to attempt to simulate the look of film. Faber discloses the technique of adding grain over an entire image. This results in the addition of grain, obviously, everywhere, including areas which don't have grain on film. As a result, this and other prior art image enhancement techniques are a two step forward, one step back exercise.
In short, a drawback to the image enhancement and manipulation technologies known in the art is that manipulation that enhances an image in one area degrades the image in another area at the same time. This is particularly true with color images. Thus, there is a need in the art for providing an apparatus and method for manipulating images which manipulates an image only in areas where manipulation is required and which avoids manipulation of an image in areas which degrade the image instead of enhancing it. It, therefore, is an object of this invention to provide a multi-dimensional color image mapping apparatus and method for selective multi-dimensional color mapping manipulation of particular color model components of an image.